DE102018117129B3 - Camera and method for controlling a camera - Google Patents

Abstract

The invention relates to a camera (2) with an image sensor (4) and a control unit (6). The image sensor (4) has a multiplicity of pixels (8), which are subdivided into at least one row of pixels (14) and associated pixel by pixel alternately at least two different pixel groups (10, 12) of the respective pixel row (14). Each pixel row (14) is divided into a plurality of segments (20) each having a plurality of pixels (8) of each pixel group (10, 12) of the respective pixel row (14). The control unit (6) is designed to determine in a step a) for a segment (20) the smallest light intensity of the pixels (8) of the first pixel group (10) as the first light intensity (L1) of this segment (20); in a step b) for this segment (20) to determine the smallest light intensity of the pixels (8) of the second pixel group (12) as the second light intensity (L2) of this segment (20); and in a step c) for this segment (20) to determine the highest light intensity from (L1) and (L2) as the third light intensity (L3) of this segment (20). In addition, the control unit (6) is designed to carry out the steps a), b) and c) for each segment (20) and to determine the largest of the third light intensities (L3) as the fourth light intensity (L4) and the camera (2). based on the fourth light intensity (L4) to control. In addition, the invention relates to a method (42) for controlling the camera (2).

Description

The invention relates to a camera and a method for controlling a camera.

Cameras are basically known from the prior art. This is, for example, a picture camera or a video camera. Particularly preferably, the camera is designed as a high-resolution industrial camera. For example, the camera can be a network camera. The camera has an image sensor. By means of the image sensor, a surveillance area of the camera can be detected optically. In this case, the image sensor on a plurality of pixels. A pixel may also be referred to as a picture cell of the image sensor. The pixels of the image sensor are often arranged in a grid pattern. This may form a plurality of rows and / or rows, each having a plurality of pixels. Each pixel of the image sensor often has a limited available dynamics. If a pixel of the image sensor is exposed, for example, over a very long period of time, there is a risk that this pixel will not yield usable information. Rather, in this case there is the danger of a so-called overexposure. The image sensor has a plurality of pixels. For each of the pixels, therefore, there is a risk of overexposure. In order to avoid this overexposure, the camera should be controlled in such a way that as far as possible none of the pixels are overexposed. This can be done for example by adjusting the exposure time, a camera aperture, and / or a sensitivity of the pixels of the image sensor. Other settings are also possible. In practice, it has therefore proved to be advantageous first to evaluate the signals of the pixels in order to determine whether and / or, where appropriate, which of the pixels is overexposed and / or underexposed. If none of the pixels are overexposed and / or underexposed, the information can also be evaluated in such a way to find a suitable setting for the camera, so that, for example, a particularly high-contrast image can be detected by means of the image sensor. In the above-described determination of an overexposure and / or underexposure, however, there is a risk that defective pixels have a negative influence on the setting of the camera. If, for example, a defective pixel is already overexposed with only a low light intensity, an information signal provided by this pixel distorts the settings valid for all pixels of the image sensor in order to avoid overexposure or underexposure.

The invention is therefore based on the object to provide a technical solution that allows adjustment of the camera so that defective pixels of the image sensor have as possible no effect on this setting.

The document US 2006/0044425 A1 describes a method and apparatus that enable the identification and correction of defective pixels and / or pixel clusters in an imaging device.

The document US 2008/0100727 A1 relates to a defect pixel correction circuit which can detect a defect of an image sensor and replace it with the correction pixel.

The document US 2010/0141810 A1 includes a method of classifying bad pixels for an image sensor having a plurality of sensor elements.

According to a first aspect of the invention, the object is achieved by a camera having the features of claim 1. Thus, a camera is provided which has an image sensor and a control unit. The image sensor has a plurality of pixels. Each pixel is configured to provide a pixel signal representing a light intensity detected by the respective pixel. The pixels of the image sensor are arranged in at least one row of pixels. The pixels of each pixel row are assigned pixel-wise alternately to at least two different pixel groups of the respective pixel row. Each pixel row is divided into a plurality of segments each having a plurality of pixels of each pixel group of the respective pixel row. The control unit of the camera is designed to determine the smallest light intensity of the light intensities detected by the associated pixels of the first pixel group as the first light intensity of this segment in a step a) for a segment. The control unit is also designed to determine the smallest light intensity of the light intensities detected by the associated pixels of the second pixel group as the second light intensity of this segment in a step b) for the segment from step a). Each control unit is also designed to determine the largest light intensity of the first light intensity and the second light intensity as the third light intensity of this segment in a step c) for the segment from step a) or b). The control unit is also designed to carry out the steps a), b) and c) for each segment in order to determine a third, associated light intensity for each segment. The control unit is also designed to determine the highest light intensity of the third light intensities as the fourth light intensity. The control unit is also configured to control the camera based on the fourth light intensity.

The control unit of the camera may include a processing unit for processing formed of data and / or signals. As previously explained, the image sensor comprises a plurality of pixels, which are arranged in at least one row of pixels. Preferably, the pixels are divided into several rows of pixels. A row of pixels is preferably to be understood as a series arrangement of pixels arranged directly behind one another. A row of pixels may extend horizontally, vertically, or diagonally across an area sensor. At least one of the rows of pixels may form a row of pixels. At least one of the pixel rows may form a pixel column. At least one of the rows of pixels may form a diagonal row of pixels. If the pixels of the image sensor are arranged, for example, in the form of a grid, several rows of pixels can be arranged one above the other. As a result, a multiplicity of pixel columns and / or diagonal rows of pixels can be formed by the same pixels.

The image sensor may be a color image sensor or a monochrome image sensor. In the monochrome image sensor, the pixels in a row of pixels may be associated with two groups of pixels. A first of these pixel groups may have pixels with a first light sensitivity. The second pixel group may include pixels having a second light sensitivity. The second light sensitivity may be greater than the first light sensitivity, or vice versa. Thus, the second pixel group may, for example, comprise pixels with particularly light-sensitive pixels and the first pixel group may have pixels with fewer photosensitive pixels. The pixels of the two pixel groups can then be arranged alternately one after the other from the two groups, so that a pixel of the first pixel group is followed by a pixel of the second pixel group, then again a pixel of the first group, etc.

In color image sensors, the pixel groups may correspond to the respective colors of the pixels. For example, a first pixel group may have green pixels and a second pixel group may have red pixels or blue pixels. It follows that the pixels of a row of pixels have alternating red and green or blue and green pixels. Each pixel row preferably has pixels of exactly two different colors, for example green and red pixels or green and blue pixels.

Each row of pixels is divided into a plurality of segments. The segments can thus subdivide the associated pixel series. Each segment has several pixels of each pixel group of the respective pixel row. The pixels of each segment preferably form pixels arranged one behind the other from the associated pixel row. For example, a segment may have two red and two green pixels if the associated pixel row has a red pixel group and a green pixel group. The same applies to the other colors of a color image sensor. Likewise, corresponding embodiments apply to monochrome image sensors if, for example, it has different pixel groups with differently light-sensitive pixels. The segments of the pixel row can be arranged directly one behind the other. In other words, the multiple segments of one pixel row may correspond to the entire pixel row. However, the image sensor and / or the associated pixels are not physically divided by the pixel rows, pixel groups and / or segments. Rather, the pixels of the image sensor can be assigned to the pixel rows, the pixel groups or the segments. The segments of a row of pixels may be formed one after the other, in particular such that all pixels of a row of pixels are assigned to the segments of the respective row of pixels. Thus, there may preferably be no pixel between the segments that is not assigned to one of the segments. The image sensor is preferably designed as a CCD sensor or as a CMOS sensor.

Although the following explanations will refer to a red pixel group having red pixels and a green pixel group having green pixels, as well as a color image sensor, the color explanations are not limited to the respective colors and / or color restricting at all. Rather, the explanations may apply analogously to other colors and / or to a monochrome image sensor.

The control unit of the camera is designed to carry out the steps a), b), c) for each segment so as to determine a third, associated light intensity for each segment. This third, associated light intensity is also referred to as the third light intensity of the respective segment.

Purely by way of example, the steps a), b), c) will be explained with reference to a color image sensor having a row of pixels with alternately arranged red and green pixels. This pixel row thus has a red pixel group and a green pixel group. The pixel row can be divided into several segments, with each segment having a total of four pixels, for example. Each segment has two green pixels and two red pixels, which are arranged alternately in succession. For example, a first red pixel may be followed by a green pixel, then a red pixel, and then another green pixel. This arrangement can apply to every segment of the pixel row. The red pixel group can form the first pixel group. The green pixel group can form the second pixel group.

If, in the aforementioned example, step a) is carried out by means of the control unit of the camera, it is first determined which of the two red pixels of a segment detects the smaller light intensity and determines it as the first light intensity of the respective segment. The same can be done for the green pixels of the same segment in step b), but here the smallest light intensity of the green pixels is determined as the second light intensity. In step c), the control unit determines which of the two light intensities of the respective segment is greater and then determines this as the third light intensity of the segment. The aforementioned steps a), b) and c) are then carried out for each segment of the image sensor. This results in a plurality of third light intensities for the corresponding plurality of segments. The largest of these third light intensities is determined by the control unit as the fourth light intensity. In addition, the control unit is configured to control the camera based on the fourth light intensity.

Investigations have shown that a defect of a pixel of an image sensor with a very high probability only occurs in isolation. Conversely, the probability is very low that several pixels arranged side by side of an image sensor are defective at the same time. In particular, the probability is particularly low that three adjacent pixels of an image sensor are defective. This examination result is advantageously used by the camera according to the invention in that the control unit is designed to carry out steps a), b) and c).

It should be noted that the pixels of each pixel row are assigned pixel-wise alternately to at least two different pixel groups of the respective pixel row. For example, the pixels of a pixel row are arranged pixel by pixel alternately with red pixels of a red pixel group and with green pixels of a green pixel group. Red and green pixels alternate. If, in step a), the smallest light intensity of the light intensity detected by the associated pixels of the first pixel group, that is, for example, the red pixels, is determined as the first light intensity of this segment, these pixels are not arranged directly next to one another but, for example, by a pixel of the other pixel group, in particular the green pixel group, separated from each other. In step a) therefore not directly adjacent pixels are examined. If one of the pixels considered in step a) is defective, for example excessively sensitive to light, which leads to a very large, detected light intensity, then this corresponding defective pixel will have no influence on the determination of the first light intensity of the associated segment. Rather, the first light intensity is determined by the other pixel of the same pixel group, that is, for example, by the other red pixel. In step b), an analogous evaluation or determination is carried out for the pixels of the other pixel group of the respective segment. Finally, in step c) it is determined by means of the control unit which of the two light intensities, namely the first light intensity and the second light intensity of the common segment, is greater in order then to use this to determine the third light intensity of this segment. The third light intensity in this case is not affected by the defective pixel of the segment.

If the defective pixel is not particularly sensitive to light, but is defective because it is particularly insensitive to light, the first light intensity is adversely affected by the defective pixel, but this negative influence is prevented in step c) from further takeover. Because in this case, the second light intensity will be greater than the first light intensity, so that the third light intensity is determined by the second light intensity. The defective pixel also has no negative influence on the third light intensity in this case.

The previously explained steps a), b) and c) have the advantageous effect that individual defective pixels have no negative influence on the determination of the third light intensity. Rather, the third light intensity is determined either by the light intensity of the non-defective red pixel or by the light intensity of the non-defective green pixel. In this way, it can be ensured in a particularly advantageous manner that individual, isolated and defective pixels have no negative influence on the determination of the third light intensity. Rather, the third light intensity is determined by non-defective pixels. By performing steps a), b), c) for each segment, a plurality of third light intensities are determined. From these third light intensities, the largest of the third light intensities is determined as the fourth light intensity. This provides information as to whether one of the segments has overexposed pixels. It can also provide information on whether the available dynamic range of the pixels of the image sensor has already been fully utilized. If this is not the case, for example, the exposure time and / or the aperture and / or other settings of the camera can be changed in order to make the most possible use of the available dynamic range of the pixels of the image sensor, which results in particularly high-contrast and / or high-quality images guaranteed. For the camera, it is therefore provided that the control unit is designed to control the camera based on the fourth light intensity.

An advantageous embodiment of the camera is characterized in that the control unit is designed to control an image acquisition by means of the image sensor of the camera based on the fourth light intensity. The image sensor is designed for image acquisition. In addition, a sensor signal representing the image captured by the image sensor may be provided by the image sensor. In order to prevent the image from having a low contrast, being too bright, too dark and / or having other negative optical properties, it is advantageous to control the image acquisition by means of the camera's image sensor based on the fourth light intensity. The control can be, for example, the control of the exposure time of the image acquisition, an aperture size of an aperture of the camera and / or a gain of the image sensor signal. The image sensor has a plurality of pixels. Each of the pixels may provide a pixel signal representing the respective detected light intensity. It is therefore also possible for the control unit to be designed to control the image acquisition by means of the image sensor of the camera based on the fourth light intensity by controlling an amplification of the pixel signals. In this case, the control of the image acquisition can be configured such that underexposure is prevented, overexposure is prevented, at least a predetermined minimum contrast is achieved, and / or other predetermined optical properties are achieved.

An advantageous embodiment of the camera is characterized in that the control unit is designed to control a brightness of the camera based on the fourth light intensity. The brightness can be achieved, for example, by adjusting an amplification factor of the sensor signal and / or the pixel signals.

A further advantageous embodiment of the camera is characterized in that each segment has a multiple of two pixels such that each segment has in each case an equal number of pixels of a first pixel group and a second pixel group. For example, each segment may have four, six, eight, ten, or another multiple of two pixels. For example, a four-pixel segment may have two green pixels and two red pixels or two green pixels and two blue pixels.

A further advantageous embodiment of the camera is characterized in that the image sensor is designed as a surface sensor or as a line sensor. In the area sensor, the pixels of the image sensor may be arranged in a grid shape or a checkerboard pattern. In the case of a line sensor, it is preferably provided that all the pixels of the image sensor are arranged in a single line or, for example, in two lines.

A further advantageous embodiment of the camera is characterized in that the pixels of the image sensor are formed with at least two different colors. In this case, the image sensor may be formed as a color image sensor. Particularly preferably, the image sensor has pixels with at least three or exactly three different colors. For example, the pixels of the image sensor may be green pixels, red pixels and blue pixels. The image sensor can therefore also be referred to as an RGB image sensor.

An advantageous embodiment of the camera is characterized in that the first pixel group of each pixel row of associated pixels is represented with a first color and the second pixel group of each pixel row of associated pixels is represented with a second, different color, so that each pixel row has a plurality of consecutively arranged pixels of alternating color. The first color may be green, for example. The second color may be, for example, red or blue. Another color combination for the first and second color is also possible. Furthermore, it is possible that the aforementioned embodiment applies analogously to monochrome image sensors. The pixels of a first color are formed by pixels having a first photosensitivity, and the pixels of the second, other color are formed by pixels having a second, different photosensitivity.

An advantageous embodiment of the camera is characterized in that the first color is green, and that the second color is red or blue. The first and second colors preferably relate to the previous embodiment of the camera. Another choice for the first or second color is also possible. For example, the first color may be red. In this case, the second color may be green or blue. But it is also possible that the first color is blue and the second color is green or red.

A further advantageous embodiment of the camera is characterized in that the image sensor is designed as a Bayer sensor. Such an image sensor is particularly advantageous as a color image sensor.

A further advantageous embodiment of the camera is characterized in that the control unit is designed to execute steps a), b) and c) as a step group, the control unit being designed to execute the step group in succession for each segment. For a segment, the step group can be executed first. before the same step group is executed for the next segment. Thus, a sequential execution of the step group for the plurality of segments can take place. For example, the step group can first be executed for a first segment of a pixel row, then for another segment, and then segment by segment. This makes it particularly easy to ensure that the step group is executed for each segment. The result of the step group is preferably the third, associated, associated light intensity for the respective segment.

1. a) Ermitteln der kleinsten Lichtintensität der von den Pixeln einer ersten Pixelgruppe des jeweiligen Segments erfassten Lichtintensitäten als eine erste Lichtintensität des jeweiligen Segments;
2. b) Ermitteln der kleinsten Lichtintensität der von den Pixeln einer zweiten Pixelgruppe des jeweiligen Segments erfassten Lichtintensitäten als eine zweite Lichtintensität des jeweiligen Segments;
3. c) Ermitteln der größten Lichtintensität der ersten Lichtintensität des jeweiligen Segments und der zweiten Lichtintensität des jeweiligen Segments als eine dritte Lichtintensität des jeweiligen Segments; und wobei das Verfahren außerdem die folgenden Schritte d) und e) aufweist:
4. d) Ermitteln der größten Lichtintensität der dritten Lichtintensitäten als eine vierte Lichtintensität mittels der Kontrolleinheit; und
5. e) Steuern der Kamera basierend auf der vierten Lichtintensität mittels der Kontrolleinheit.

According to a second aspect of the invention, the object mentioned at the outset is achieved by a method having the features of claim 11. Thus provided is a method for controlling a camera having an image sensor and a control unit, wherein the image sensor has a plurality of pixels, each pixel for Providing a pixel signal which represents a light intensity detected by the respective pixel, the pixels of the image sensor are arranged in at least one pixel row, the pixels of each pixel row are assigned pixel-wise alternately at least two different pixel groups of the respective pixel row, each pixel row is divided into a plurality of pixels Segments each having a plurality of pixels of each pixel group of the respective pixel row is structured, and wherein the method comprises the following steps a) to c), which are carried out for each segment by means of the control unit:

1. a) determining the lowest light intensity of the light intensities detected by the pixels of a first pixel group of the respective segment as a first light intensity of the respective segment;
2. b) determining the minimum light intensity of the light intensities detected by the pixels of a second pixel group of the respective segment as a second light intensity of the respective segment;
3. c) determining the maximum light intensity of the first light intensity of the respective segment and the second light intensity of the respective segment as a third light intensity of the respective segment; and wherein the method further comprises the following steps d) and e):
4. d) determining the maximum light intensity of the third light intensities as a fourth light intensity by means of the control unit; and
5. e) controlling the camera based on the fourth light intensity by means of the control unit.

With regard to the method, reference is made to the preceding explanations, preferred features, effects and / or advantages and reference is made at least in an analogous manner as explained in connection with the camera according to the first aspect of the invention and / or one of the associated advantageous embodiments are. This applies in particular to the method steps a), b), c). With regard to method steps d) and e), it has already been explained in connection with the camera according to the first aspect of the invention that the control unit of the camera is preferably configured and / or designed to execute these method steps d) and e). A repetition of the advantages and effects is therefore omitted at this point.

An advantageous embodiment of the method is characterized in that step e) comprises controlling an image acquisition by means of the image sensor of the camera based on the fourth light intensity. With regard to the control of image acquisition, reference is made to the advantageous explanations, preferred features, effects and / or advantages in an analogous manner, as they have already been explained in a corresponding manner in connection with the camera.

A further advantageous embodiment of the method is characterized in that the first pixel group of each pixel row of associated pixels is represented by a first color and wherein the second pixel group of each pixel row of associated pixels is represented by a second, different color, so that each pixel row has a plurality of pixels of alternating colors arranged one behind the other.

A further advantageous embodiment of the method is characterized in that the first color is green and that the second color is red or blue.

A further advantageous embodiment of the method is characterized in that steps a) to c) are carried out successively as a step group for each segment.

• 1 zeigt eine vorteilhafte Ausgestaltung der Kamera in einer schematischen Ansicht.
• 2 zeigt eine vorteilhafte Pixelanordnung des Bildsensors der Kamera in einer schematischen Darstellung.
• 3 zeigt eine vorteilhafte Ausgestaltung einer Pixelreihe in einer schematischen Darstellung.
• 4 zeigt eine vorteilhafte Ausgestaltung eines Ablaufplans in einer schematischen Darstellung.
• 5 zeigt eine vorteilhafte Ausgestaltung eines Ablaufplans des Verfahrens.

Other features, advantages and applications of the present invention will become apparent from the following description of the embodiments and the figures. All described and / or illustrated features alone and in any combination form the subject matter of the invention, regardless of their composition in the individual claims or their back references. In the figures, the same reference numerals for identical or similar objects.

• 1 shows an advantageous embodiment of the camera in a schematic view.
• 2 shows an advantageous pixel arrangement of the image sensor of the camera in a schematic representation.
• 3 shows an advantageous embodiment of a row of pixels in a schematic representation.
• 4 shows an advantageous embodiment of a flowchart in a schematic representation.
• 5 shows an advantageous embodiment of a flowchart of the method.

In the 1 is the camera 2 shown schematically in an advantageous embodiment. The camera 2 has an image sensor 4 and a control unit 6 on. In addition, the camera can 2 a housing 22 respectively. The control unit 6 is inside the case 22 arranged. In addition, the image sensor 4 completely or at least partially within the housing 22 arranged. Preferably, the housing has 22 an opening through which light onto the image sensor 4 can meet. This aperture may be coupled to an aperture to determine the effective cross-sectional area for incident light on the image sensor 4 to control. The aperture can be controlled by the control unit 6 be controlled directly or indirectly. In addition, on the housing 22 a mounting connection 24 be arranged. This mounting connection 24 may be formed for attaching a lens and / or a lens. The mounting connection 24 can have an internal thread or an external thread. The mounting connection 24 is preferably coaxial with the image sensor 4 arranged.

The camera 2 can also have a signal interface 26 respectively. The signal interface 26 is preferably designed as a network interface. The signal interface 26 is preferably via a signal line 28 with the control unit 6 coupled. The control unit 6 is preferably also via a further signal line 30 with the image sensor unit 4 coupled. By means of this signal line 30 For example, signals, in particular an image sensor signal or the pixel signals, from the image sensor unit 4 to the control unit 6 be transmitted. The control unit 6 can have multiple subunits. One of these subunits may be a data processing unit. Via the signal line 28 between the control unit 6 and the signal interface 26 can send an image signal to one via the signal interface 26 coupled receiving unit, in particular a server and / or a network-capable computer, are transmitted. The camera 2 is preferably a network camera.

The image sensor 4 the camera 2 has a variety of pixels 8th on. In this context, on the 2 directed. In the 2 is a pixel array with a plurality of pixels 8th shown. However, this pixel arrangement is merely illustrative and not intended to be limiting. In this pixel arrangement are the pixels 8th arranged in a grid, so from the pixels 8th several pixel lines 32 , several pixel columns 34 and several pixel diagonal rows 36 are formed. Each of the pixel line 32 , Pixel column 34 and / or pixel diagonal row 36 can as a pixel row 14 be understood. If following from a pixel row 14 is spoken, so for example, a pixel line 32 , a pixel column 34 or a pixel diagonal row 36 be meant.

The pixels 8th of the image sensor 4 the camera 2 are in several pixel rows 14 divided. In this context, on the 3 referenced, in which a pixel row 14 , in this case exemplified by a pixel line 32 , is shown. However, the following explanations apply to each of the possible pixel rows 14 in an analogous way. The pixels 8th . 16 . 18 every pixel row 14 are pixel by pixel alternately at least two different pixel groups 10 . 12 the respective pixel row 14 assigned. The crossed hatched pixels 16 the pixel row 14 For example, you can use the first pixel group 10 be assigned. The diagonally hatched pixels 18 for example, the second pixel group 12 be assigned. The pixels 16 the first pixel group 10 For example, green pixels 16 his. The pixels 18 the second pixel group 12 for example, red pixels 18 his. Like from the 3 Therefore, at least indirectly, the green pixels are 16 the first pixel group 10 and the red pixels 18 the second pixel group 12 arranged alternately.

It is also intended that every pixel row 14 into a plurality of segments 20 is articulated. Every segment 20 has several pixels 16 or. 18 of each pixel group 10 . 12 on. Like from the 3 As an example, each segment can 20 four pixels 8th include. With reference to the example explained above, each segment 20 for example, two green pixels 16 the first pixel group 10 and two red pixels 18 the second pixel group 12 respectively.

Through the rows of pixels 14 . 32 . 34 . 36 , Pixel groups 10 . 12 and / or segments 20 becomes the image sensor 4 not physically broken. Rather, the pixels can 8th of the image sensor 4 the pixel rows 14 . 32 . 34 . 36 , the pixel groups 10 . 12 , and / or the segments 20 be assigned functionally and / or logically.

The control unit 6 is trained for each segment 20 to carry out the steps a), b) and c). These steps are schematically illustrated in the process flowchart in FIG 5 shown. A corresponding logic flowchart is in the 4 to be referred to in the further reference.

The control unit 6 is formed in the step a) for the segment 20 the smallest light intensity of the associated pixels 16 the first pixel group 10 detected light intensities P1 . P2 as the first light intensity L1 this segment 20 to investigate.

In practice, it can happen that one of the two pixels 16 is defective. This pixel 16 can then be considered a broken pixel 40 be designated. The other of the two pixels 16 can as a non-defective pixel 38 be designated. The broken pixel 40 For example, it may be excessively light-sensitive or particularly light-sensitive, and it may be so photosensitive as it is not intended. At a low light irradiation, this can then lead to this defective pixel 40 overexposure takes place within a very short time, so the pixels of this defective 40 detected, falsified light intensity P1 is especially big. The non-defective pixel 38 In practice, light of approximately similar light intensity is applied. The non-defective pixel 38 recorded light intensity P2 however, is significantly smaller than that of the defective pixel 40 recorded light intensity P1 , If the control unit now executes step a), forms the light intensity P2 the non-defective pixel 38 the first light intensity L1 , By the previously explained determination of the first light intensity L1 can thus influence the influence of a defective pixel 40 on the determination of the first light intensity L1 be prevented.

Basically, however, there is usually the assumption that neither of the two pixels 16 the first pixel group 10 is defective. In this case, those of these two pixels 16 detected light intensities P1 . P2 in about the same size. However, the slightly smaller light intensity than the first light intensity L1 for this segment 20 certainly. The first light intensity thus determined L1 however, offers the option of knowing the actual exposure of the pixels 16 To give information. Is the first light intensity L1 for example, so great that it can be concluded that overexposure of both pixels, so this is the first light intensity L1 suitable for further use of the camera. Because an overexposure of the pixels 16 should be avoided.

An overexposure of the pixels 16 however, is only one case of many possible cases. The exposure of the pixels 16 can also be done such that neither of the two pixels 16 overexposed. In this case also the first light intensity determined in an analogous manner becomes L1 represent a corresponding information.

Like from the 4 can be seen schematically, the segment has 20 but also pixels 18 a second pixel group 12 on. The control unit 6 is therefore adapted to a step b) for the segment 20 the smallest light intensity of the associated pixels 18 the second pixel group 12 detected light intensities P3 . P4 as the second light intensity L2 this segment 20 to investigate. Assuming that both pixels 18 the second pixel group 12 are not broken, those of these pixels 18 detected light intensities P3 . P4 only slightly different, so the second light intensity L2 from the very probably only slightly smaller light intensity of the two light intensities P3 . P4 is determined. As in an analogous way for the first light intensity L1 there has been a possibility that the pixels 18 the second pixel group 12 are not overexposed or that the pixels 18 just completely overexposed.

As explained before, give the first light intensity L1 as well as the second light intensity L2 itself robust against possible influences of a defective pixel 40 Reliable information about it, such as the exposure of the segment 20 is. In a step c) is therefore by means of the control unit 6 the light intensity of the first light intensity L1 and the second light intensity L2 as the third light intensity L3 certainly, which is bigger. In other words, the control unit 6 adapted to, in a step c) for the segment 20 the largest light intensity of the first light intensity L1 and the second light intensity L2 as the third light intensity L3 this segment 20 to determine. Although one of the pixels 40 of the segment 20 is defective, is the third light intensity L3 of the segment 20 Reliably recyclable. As the control unit 6 is formed, for each segment 20 steps a), b) and c), preferably in groups for each of the segments 20 To carry out, by means of the control unit 6 for each segment 20 a third, associated light intensity L3 be determined. This in 4 illustrated logic diagram for determining the third light intensity L3 so can for each segment 20 be provided. For a better overview, however, was on the corresponding representation in 4 waived.

The control unit 6 is also formed, the largest light intensity of the third light intensities L3 as the fourth light intensity L4 to investigate. Because the multitude of third light intensities L3 due to the pixel arrangement, as shown for example in the 2 is different from one another, is the largest third light intensity L3 of special interest. Because this provides information about whether one of the pixels of one of the segments 20 overexposed. Therefore, the largest light intensity of the plurality of third light intensities L3 also as the fourth light intensity L4 certainly. Gives this fourth light intensity L4 find out that an overexposure of at least one of the pixels 8th is present, the camera is preferably from the control unit 6 to control such that the exposure time is shortened and / or that an aperture is reduced. It is therefore intended that the control unit 6 is trained, the camera 2 based on the fourth light intensity L4 to control. The control may relate, for example, to the exposure time, the aperture size and / or the gain of the sensor signal and / or the pixel signals. This makes it possible for the control unit 6 the brightness of the camera 2 based on the fourth light intensity L4 controls. Based on the aforementioned explanations, this control is particularly robust against possible influences of defective pixels 40 , Because this negative effect can in particular by the control unit 6 executable steps a), b) and c) are prevented. In the 5 is an advantageous embodiment of the method 42 shown. Preferably, the method 42 designed and / or configured to use the camera 2 to be executed.

The method comprises the steps a), b) and c), preferably in groups in the order mentioned for each segment 20 by means of the control unit 6 be executed. According to step a), the smallest light intensity of the pixels is determined 16 the first pixel group 10 of the segment 20 detected light intensities P1 . P2 as the first light intensity L1 , According to a step b) of the method 42 a determination is made of the smallest light intensity of the pixels 18 the second pixel group 12 of the segment 20 detected light intensities P3 . P4 as the second light intensity L2 of the segment 20 , According to step c) of the method, the greatest light intensity of the first light intensity is determined L1 of the segment 20 and the second light intensity L2 of the segment 20 as the third light intensity L3 this segment 20 , In addition, the method points 42 steps d) and e). Steps d) and e) are carried out following the execution of steps a) to c) for each of the segments. According to step d) of the method 42 the maximum light intensity of the third light intensities is determined L3 as the fourth light intensity L4 by means of the control unit 6 , According to step e) of the method 42 the camera is controlled 2 based on the fourth light intensity L4 by means of the control unit 6 ,

In addition, it should be noted that "having" does not exclude other elements or steps, and "a" or "an" does not exclude a plurality. It should also be appreciated that features described with reference to any of the above embodiments may also be used in combination with other features of other embodiments described above. Reference signs in the claims are not to be considered as limiting.

LIST OF REFERENCE NUMBERS

P1

Light intensity of pixels

P2

Light intensity of pixels

P3

Light intensity of pixels

P4

Light intensity of pixels

L1

first light intensity

L2

second light intensity

L3

third light intensity

L4

fourth light intensity

2

camera

4

image sensor

6

control unit

8th

pixel

10

first pixel group

12

second pixel group

14

pixel row

16

Pixels of the first pixel group

18

Pixels of the second pixel group

20

segment

22

casing

24

Mount Termination

26

Signal interface

28

signal line

30

signal line

32

pixel line

34

pixel column

36

Pixel Diagonal row

38

non-defective pixel

40

broken pixel

Claims (16)

A camera (2) comprising: an image sensor (4) and a control unit (6); wherein the image sensor (4) comprises a plurality of pixels (8); wherein each pixel (8) is adapted to provide a pixel signal representing a light intensity detected by the respective pixel (8); wherein the pixels (8) of the image sensor (4) are arranged in at least one row of pixels (14); wherein the pixels (8) of each row of pixels (14) are assigned, pixel by pixel, alternately at least two different groups of pixels (10, 12) of the respective row of pixels (14); each one Pixel row (14) is divided into a plurality of segments (20) each having a plurality of pixels (8), each pixel group (10, 12) of the respective pixel row (14); wherein the control unit (6) is configured, in a step a), for a segment (20), the smallest light intensity of the light intensities detected by the associated pixels (8) of the first pixel group (10) as the first light intensity (L1) of this segment (20 ) to investigate; wherein the control unit (6) is configured, in a step b) for the segment (20) from step a), the smallest light intensity of the light intensities detected by the associated pixels (8) of the second pixel group (12) as the second light intensity (L2) to determine this segment (20); wherein the control unit (6) is designed, in a step c) for the segment (20) from step a) and b), the maximum light intensity of the first light intensity (L1) and the second light intensity (L2) as the third light intensity (L3) to determine this segment (20); wherein the control unit (6) is designed to carry out for each segment (20) the steps a), b) and c) in order to determine for each segment (20) a third, associated light intensity (L3); wherein the control unit (6) is adapted to determine the highest light intensity of the third light intensities (L3) as the fourth light intensity (L4); and wherein the control unit (6) is configured to control the camera (2) based on the fourth light intensity (L4). Camera (2) according to the preceding claim, characterized in that the control unit (6) is designed to control image acquisition by means of the image sensor (4) of the camera (2) based on the fourth light intensity (L4). Camera (2) according to one of the preceding claims, characterized in that the control unit (6) is designed to control the brightness of the camera (2) based on the fourth light intensity (L4). Camera (2) according to one of the preceding claims, characterized in that each segment (20) has a multiple of two pixels (8) in such a way that each segment (20) has in each case an equal number of pixels (8) of a first pixel group ( 16) and a second pixel group (18). Camera (2) according to one of the preceding claims, characterized in that the image sensor (4) is designed as an area sensor or a line sensor. Camera (2) according to one of the preceding claims, characterized in that the pixels (8) of the image sensor (4) are formed with at least two different colors. A camera (2) according to the preceding claim, characterized in that the first pixel group (16) of each pixel row (14) of associated pixels (8) is represented by a first color and wherein the second pixel group (18) of each row of pixels (14 ) of associated pixels (8) is represented by a second, different color such that each row of pixels (14) has a plurality of successively arranged pixels (8) of alternating color. Camera (2) after one of the previous ones Claims 6 to 7 , characterized in that the first color is green, and that the second color is red or blue. Camera (2) after one of the previous ones Claims 6 to 8th , characterized in that the image sensor (4) is designed as a Bayer sensor. Camera (2) according to one of the preceding claims, characterized in that the control unit (6) is designed to execute steps a), b) and c) as a step group, and wherein the control unit (6) is designed, the step group successively for to execute each segment (20). Method for controlling a camera (2) having an image sensor (4) and a control unit (6), the image sensor (4) having a multiplicity of pixels (8), each pixel (8) being designed to provide a pixel signal comprising a represents the light intensity detected by the respective pixel (8), the pixels (8) of the image sensor (4) are arranged in at least one pixel row (14), the pixels (8) of each pixel row (14) alternate pixel by pixel at least two different pixel groups (10 , 12) of the respective pixel row (14), each pixel row (14) is divided into a plurality of segments (20) each having a plurality of pixels (8) of each pixel group (10, 12) of the respective pixel row (14), and the method comprising the following steps a) to c) carried out for each segment (20) by means of the control unit (6): a) determining the smallest light intensity of the pixels (8) of a first pixel group (10) of the respective one segment (20) detected light intensities as a first light intensity (L1) of the respective segment (20); b) determining the minimum light intensity of the light intensities detected by the pixels (8) of a second pixel group (12) of the respective segment (20) as a second light intensity (L2) of the respective segment (20); c) determining the maximum light intensity of the first light intensity (L1) of the respective segment (20) and the second light intensity (L2) of the respective segment as a third light intensity (L3) of the respective segment (20); and wherein the method further comprises the steps of: d) determining the highest light intensity of the third light intensities (L3) as a fourth light intensity (L4) by means of the control unit (6); and e) controlling the camera (2) based on the fourth light intensity (L4) by means of the control unit (6). Method according to the preceding claim, characterized in that step e) comprises controlling image acquisition by means of the image sensor (4) of the camera (2) based on the fourth light intensity (L4). Method according to the preceding claim, characterized in that step e) comprises controlling a brightness of the image acquisition based on the fourth light intensity (L4). Method according to one of the preceding Claims 11 to 13 characterized in that the first pixel group (10) of each pixel row (14) of associated pixels (8) is represented by a first color, and wherein the second pixel group (12) of each pixel row (14) is associated with associated pixels (8) a second, different color is represented, so that each pixel row (14) has a plurality of successively arranged pixels (8) with alternating color. Method according to the preceding claim, characterized in that the first color is green and that the second color is red or blue. Method according to one of the preceding Claims 11 to 15 , characterized in that the steps a) to c) are carried out successively as a step group for each segment (20).

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